CVE-2026-88964

An integer underflow in OpenVPN version 2.7_alpha3 through 2.7.7 on Windows and Android allows...

7.1 HighFix available

An integer underflow in OpenVPN version 2.7_alpha3 through 2.7.7 on Windows and Android allows remote authenticated servers to cause a denial of service or memory disclosure via crafted domain search options

Attack profile

How easy it is to exploit

Attack vector: Network
Complexity: Low
Privileges needed: Low
User interaction: None

What an attacker can affect

Confidentiality: Low
Integrity: None
Availability: High

Exploit likelihood

0.38%Down 0.1 points since Oct 14, 2026

What each source reports

CVE List Score used 7.1

Record: CVE-2026-88964
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
Weakness: CWE-191, CWE-125
Updated: 2026-11-02

EUVDEUVD-2026-100755 7.1

Record: EUVD-2026-100755
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N
Updated: 2026-11-02

GitHub AdvisoriesGHSA-wm7f-2ghj-7r8c 7.1

An integer underflow in OpenVPN version 2.7_alpha3 through 2.7.7 on Windows and Android allows...

Record: GHSA-wm7f-2ghj-7r8c
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness: CWE-125
Updated: 2026-11-02

NVD 7.1

Record: CVE-2026-88964
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Weakness: CWE-125, CWE-191
Updated: 2026-11-02

OSVDEBIAN-CVE-2026-88964 7.1

Record: DEBIAN-CVE-2026-88964
CVSS 4.0: 7.1 HighCVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:L/VI:N/VA:H/SC:N/SI:N/SA:N/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
Updated: 2026-11-02

OSVUBUNTU-CVE-2026-88964 No score

[Unknown description]

Record: UBUNTU-CVE-2026-88964
Updated: 2026-11-02

Affected products

openvpn

Affected packages

Affected packages
Package	Affected	Fixed
`openvpn` Debian:12	All versions, plus listed versions 2.6.11-12.6.12-12.6.13-12.6.14-0+deb12u12.6.14-0+deb12u2 Show 40 moreShow less 2.6.14-12.6.14-22.6.15-12.6.3-12.6.3-1+deb12u12.6.3-1+deb12u1~bpo11+12.6.3-1+deb12u22.6.3-1+deb12u2~bpo11+12.6.3-1+deb12u32.6.3-1+deb12u42.6.3-22.6.3-2.12.6.7-12.6.9-12.7.0-12.7.0-1~bpo13+12.7.0~alpha1-12.7.0~alpha2-12.7.0~alpha3-12.7.0~beta1-12.7.0~beta2-12.7.0~beta3-12.7.0~rc1-12.7.0~rc2-12.7.0~rc2-22.7.0~rc3-12.7.0~rc4-12.7.0~rc5-12.7.0~rc6-12.7.1-12.7.1-1~bpo13+12.7.2-12.7.2-1~bpo13+12.7.3-12.7.5-12.7.5-1~bpo13+12.7.7-12.7.7-1~bpo13+12.7.8-12.7.8-1~bpo13+1	None known
`openvpn` Debian:13	All versions, plus listed versions 2.6.14-12.6.14-1+deb13u12.6.14-1+deb13u22.6.14-1+deb13u32.6.14-2 Show 27 moreShow less 2.6.15-12.7.0-12.7.0-1~bpo13+12.7.0~alpha1-12.7.0~alpha2-12.7.0~alpha3-12.7.0~beta1-12.7.0~beta2-12.7.0~beta3-12.7.0~rc1-12.7.0~rc2-12.7.0~rc2-22.7.0~rc3-12.7.0~rc4-12.7.0~rc5-12.7.0~rc6-12.7.1-12.7.1-1~bpo13+12.7.2-12.7.2-1~bpo13+12.7.3-12.7.5-12.7.5-1~bpo13+12.7.7-12.7.7-1~bpo13+12.7.8-12.7.8-1~bpo13+1	None known
`openvpn` Debian:14	before 2.7.8-1, plus listed versions 2.6.14-12.6.14-22.6.15-12.7.0-12.7.0-1~bpo13+1 Show 23 moreShow less 2.7.0~alpha1-12.7.0~alpha2-12.7.0~alpha3-12.7.0~beta1-12.7.0~beta2-12.7.0~beta3-12.7.0~rc1-12.7.0~rc2-12.7.0~rc2-22.7.0~rc3-12.7.0~rc4-12.7.0~rc5-12.7.0~rc6-12.7.1-12.7.1-1~bpo13+12.7.2-12.7.2-1~bpo13+12.7.3-12.7.5-12.7.5-1~bpo13+12.7.7-12.7.7-1~bpo13+12.7.8-1~bpo13+1	2.7.8-1

History

History
Recorded	Changed	Sources
Nov 3, 2026	affected
Nov 2, 2026	first indexed	CVE List, EUVD, GitHub Advisories, NVD, OSV

Dates are when Every CVE recorded each change. Upstream dates may differ.

In short

CVE-2026-88964 is a high vulnerability (CVSS 7.1) in Openvpn, published October 8, 2026. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 0.38%, the 31st percentile. Fixed in openvpn 2.7.8-1.